Search PubMed⌕ Search

Biomedical subjects

M Calabresi

Publications and source records attributed to M Calabresi.

11 recordsLinked to original sources
PubMed2000

Complement C1q is dramatically up-regulated in brain microglia in response to transient global cerebral ischemia.

Recent evidence suggests that the pathophysiology of neurodegenerative and inflammatory neurological diseases has a neuroimmunological component involving complement, an innate humoral immune defense system. The present study demonstrates the effects of experimentally induced global ischemia on the biosynthesis of C1q, the recognition subcomponent of the classical complement activation pathway, in the CNS. Using semiquantitative in situ hybridization, immunohistochemistry, and confocal laser scanning microscopy, a dramatic and widespread increase of C1q biosynthesis in rat brain microglia (but not in astrocytes or neurons) within 24 h after the ischemic insult was observed. A marked increase of C1q functional activity in cerebrospinal fluid taken 1, 24, and 72 h after the ischemic insult was determined by C1q-dependent hemolytic assay. In the light of the well-established role of complement and complement activation products in the initiation and maintenance of inflammation, the ischemia-induced increase of cerebral C1q biosynthesis and of C1q functional activity in the cerebrospinal fluid implies that the proinflammatory activities of locally produced complement are likely to contribute to the pathophysiology of cerebral ischemia. Pharmacological modulation of complement activation in the brain may be a therapeutic target in the treatment of stroke.

Animals↗
PubMed1993

[Videolaparoscopic cholecystectomy. Experience, evolution, and comparison of techniques].

The paper broadly outlines the technique of laparoscopic cholecystectomy used by the authors to treat patients suffering from calculosis of the gallbladder. Basing their comments on the French school, the authors review the literature to identify those innovations introduced by individual operators in elation to the original technique which have enabled this method to be extended to those cases complicated by acute cholecystitis, VBP calculosis or sequelae from abdominal surgery. The most important innovations include the use of a laparoscope with oblique 30-degrees vision, which is extremely useful during the dissection of Calot's triangle since it allows VBP to be identified with greater ease and precision, above all in the event of phlogistic sequelae enclosing the peduncle. In addition, laparoscopic suture or ligation using Roeder's running-knot, used by the Dundee school to treat the cystic duct and artery, presents considerable advantages compared to the conventional use of metal clips. The authors also emphasise the growing return to intraoperative cholangiography which is routinely performed by some authors and is of value in identifying anatomic anomalies, iatrogenic lesions and VBP calculi unnoticed by preoperative tests. A second innovation which is highlighted consists of the treatment of choledocholithiasis during the course of laparoscopic cholecystectomy, in addition to pre- and postoperative endoscopic papillo-sphincterotomy.

Adult↗
PubMed1992

Evidence for a direct vasoconstrictor effect of big endothelin-1 in the rat kidney.

Inhibition of endothelin-1 (ET-1)-converting enzyme has been suggested as a strategy for blocking ET-1-mediated vasoconstriction. However, it is unclear whether its putative substrate, bigET-1, is an inactive precursor. Thus, we compared in the rat the effects of ET-1 and bigET-1 on renal vascular resistance (RVR) in vitro (isolated perfused kidney, n = 15) and in vivo (Doppler shift technique, n = 23) when injected i.v. or in the rat renal artery (i.a.), before and after metalloprotease inhibition with phosphoramidon (30 mg/kg i.v.). In vitro, the ET-1/bigET-1 potency ratio for the RVR increase was 175; in vivo (i.v.) it was approximately 7 (ED50: 99 and 692 pmol/kg, respectively; P < 0.01). Unlike that of ET-1, the bigET-1 effect started slowly (peak effect at 15 min). On i.a. injection, the ED50 of ET-1 was lower but that of big ET-1 was unchanged (ED50: 28 and 706 pmol/kg, respectively). Moreover, the effect of i.a. bigET-1 on RVR was biphasic, with a dose-related rapid increase followed by a slowly developing further rise. Phosphoramidon completely inhibited the hemodynamic effects of i.v. bigET-1, but abolished only the second phase of the response when given i.a. It also significantly enhanced the effect of ET-1. We conclude that in the rat: (1) bigET-1 may affect RVR by both a direct effect and through phosphoramidon-sensitive conversion to ET-1; (2) the direct vasoconstrictor effect of bigET-1 might be expressed during endothelin-converting enzyme inhibition; (3) metalloproteases are involved in ET-1 degradation.

Animals↗
PubMed1986

Why not extrasystoles?

Explore the source record for details and available documents.

Cardiac Complexes, Premature↗
PubMed1978

Echocardiographic and clinical correlations in systemic hyper-tension.

Echocardiographic measurements in 47 asymptomatic hypertensive patients were correlated with duration and severity of blood pressure elevation and with optic fundoscopic findings. These observations were also compared with electrocardiographic and chest roentgenographic measurements. Echo left ventricular wall thickness (LVWT) correlated best with duration of known hypertension. For 22 recent hypertensive patients the LVWT mean was .9 +/- .3 cm whereas mean LVWT for 25 patients hypertensive for five or more years was 1.3 +/- .2, (p less than or equal to .01). More severe initial diastolic pressure and the presence of hypertensive fundi also correlated with increased wall thickness. Increased left atrial diameter (greater than or equal to 2 cm m2) was observed primarily in the presence of longstanding disease. ECG and cardiothoracic ratio by xray did not correlate highly with the echo abnormalities. These observations suggest that echocardiography may be a sensitive and early means of recognizing cardiac changes in hypertensive patients.

Adult↗
PubMedDate not supplied

[The prevalence of smoking in psychiatric patients. The effect of "institutionalization"].

The prevalence and other parameters concerning tobacco smoking were assessed in 100 outpatients with psychiatric disorders of axis I and II, according to DSM-III R criteria, and compared with those of 85 male psychiatric inpatients with forensic problems, recruited in a psychiatric hospital. The use of tobacco smoking was increased in psychiatric outpatients vs. the general pupulation and was very heightened in schizophrenic, as reported in earlier investigations; in the forensic sample both schizophrenic and non schizophrenic patients showed a very high prevalence. Therefore, the factor "institutionalization" does not modify the prevalence of tobacco smoking in schizophrenic--whose "smoking disposition" appears independent of the different social environments--while increasing the use in non schizophrenic patients. The positive correlation between tobacco smoking and schizophrenia is largely supported by these data and demands further investigation of its pathophysiologic mechanisms.

Adult↗
PubMedDate not supplied

[Chronic dialysis and forcing of the ability to fantasize. Evaluation of the alexithymic phenomenon in a group of dialyzed patients].

In order to evaluate personality modifications toward greater concreteness and a consequent reduction of fantasizing in subjects undergoing chronic haemodialytic treatment, the Shalling Sifneos Personality Scale (S.S.P.S.) was administered to a group of patients undergoing dialysis and to two control groups: one consisting of patients with chronic hepatitis and the other of healthy subjects. The S.S.P.S. measures the alexithymic traits of the personality. Subjects undergoing dialysis scored significantly higher than chronic hepatitis patients and healthy subjects; the latter group had the lowest scores. The alexithymic score, moreover, appears to be directly correlated with the duration of dialysis. It is suggested that the prominence of the alexithymic phenomenon may be related to defense mechanisms against recurrent anguish about dying and to the tendency to assume certain characteristics of the particular therapeutic regimen, such as concreteness and rationality, so as to be able to tolerate the aggressive aspects of the treatment.

Adolescent↗